Currently, a liquid crystal module (LCM) and an open cell mainly adopt LVDS to perform display signal transmission.
Generally, LVDS is transmitted by more than four pairs of differential signal lines, each pair having two wires between which there is a 100Ω matching resistor for impedance matching.
An LVDS driver and an LVDS receiver are the most basic LVDS devices; as shown in FIG. 1, the LVDS driver is composed of a current source, which is used for driving a pair of LVDS lines and has a current of usually 3.5 mA, and the LVDS receiver has a very high input impedance; therefore, most of the current output by the LVDS driver flows through the 100Ω matching resistor, and a voltage of about 350 mV is generated at the input end of the LVDS receiver.
In the process of producing an LCM and an open cell, the LVDS interface matching resistor in the drive circuit board often falls off to get lost, which causes poor image output of the LCM and the open cell. Because there are many resistors and other components on the drive circuit board, it is difficult to find the loss of the matching resistor in time, thus influencing efficiency of the product failure analysis.
In addition, under the condition of faulty soldering LVDS interface matching resistor, it is almost impossible to find the matching resistor anomaly in appearance, and the only way is through a manual way to detect every matching resistor using an electronic multimeter; therefore, it is difficult and time consuming to find the abnormal matching resistor, which makes it more difficult for the product failure analysis.